| Abstract | Hydrogen production from glycerol was studied in a microbial electrolysis cell (MEC) with a 250 mL anodic chamber and a gas-phase cathode. A membraneless MEC design was employed, where a graphite felt anode and gas diffusion cathode were only separated by a 0.7 mm thick highly porous synthetic fabric (J-cloth). Glycerol (fuel) was continuously fed to the anodic chamber at loads of 0.3-5.3 g La⁻¹ d⁻¹. Fast conversion of glycerol to fermentation products, mainly 1,3-propanediol, propionate, and acetate was observed, that is, the fermentation products rather than glycerol were the most likely source of electrons for the anodophilic microorganisms. Hydrogen formation at the cathode required additional input of energy, which was provided by a controllable power supply. Hydrogen formation was observed starting from an applied voltage of 0.5 V. The highest volumetric rate of hydrogen production was 0.6 L La⁻¹ d⁻¹, which was obtained at a glycerol load of 2.7 gLa⁻¹ d⁻¹ and an applied voltage of 1.0 V. Hydrogen yield reached 5.4 mol per mol glycerol consumed, which corresponded to 77% of the theoretical value. |
|---|
